A 67-year-old nontoxic appearing male patient with a history of coronary artery disease, hyperlipidemia, transient ischemic attack, gout, renal colic, and squamous cell carcinoma presents with concern for multiple new painful lesions on his body. The rash first appeared five months ago but disappeared for some time before reappearing. It has worsened over the past few weeks. He has pain, erythema, pruritus, and urticarial, blistering, crusted lesions. He has had clear drainage from ruptured blisters. His only recent change in medication is an increase in his allopurinol (initiated four months ago; increased three weeks ago). He has tried Benadryl and steroids with minimal relief and is quite frustrated as this is his fourth emergency department visit for this complaint.
Skin: Multiple areas of 1-3 cm bullae (both tense and flaccid as well as open/ulcerated) on the trunk, groin, axilla, inguinal folds, palms, and dorsum of feet, not on soles; papules coalesce into annular plaques; no mucosal involvement
This patient has bullous pemphigoid. Also included on the differential is bullous lupus erythematosus, urticaria, DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms), epidermolysis bullosa, and erythema multiforme.
Diagnosis may be made through clinical recognition of the typical features. The workup for a definitive diagnosis begins with histopathologic direct immunofluorescence from a skin biopsy of the edge of a blister and the surrounding normal-appearing skin, which is then confirmed with indirect immunofluorescence of the patient’s serum.
Bullous pemphigoid is a chronic, inflammatory, subepidermal, blistering disease. It is the result of an attack on the basement membrane of the epidermis by IgG +/-IgE immunoglobulins and activated T lymphocytes.
It primarily affects elderly individuals in their 50s-70s, with an average age at onset of 65 years, and is often associated with stroke or dementia.
The most common treatments for bullous pemphigoid are anti-inflammatories (topical and oral steroids), immunosuppressants, and doxycycline. Treatment regimens are aimed to minimize the systemic side effects of the treatment itself, while also decreasing inflammation, blister formation, and autoantibody production.